Actually, the last time we addressed this was on 7/4/11 (check the QoD Archives) but it was a pretty short answer, at least by Question of the Day standards, on account of the fact that there aren't many casinos that do much for birthdays. But here's what we've got.
For one thing, unless you're a member of the players club, you can pretty much forget about getting anything from any casino or gaming bar on your birthday, so that's just one more good reason to always sign up, even if you only visit an establishment very infrequently. You might, in some instances, be able to sign up on your special day and still enjoy whatever the birthday bonus is, but for others you may already have to be in the system.
Even if you are a member of the players club, the casinos don't exactly jump up and down for their patrons' anniversaries (unless you're a big player, in which case we're thinking they might be inclined to push the boat out a little more). The current writer doesn't play much, but I am a member of a lot of players clubs (see note above!), including the main locals ones (Stations, Boyd, etc.) and it just happens to be my birthday later this month. I can confirm that to-date, I have received not a single specific birthday offer or bonus from any casino.
However, I have received free play from a number of bars, including $20 from Money Plays (where I haven't played a bean in at least six months, although I have popped in for the occasional taco), plus $40 from McMullan's Irish Pub by the Orleans (I used to play there with some regularity, but it had been so long their entire player's club had changed and I had a key fob when I needed a card! They did still honor my $40, though). So, it really does pay just to sign up and give them your details. Dotty's can be pretty generous with birthday freeplay, too.
As far as the casinos go, before the economy crashed things used to be somewhat more generous. Once upon a time, the Palms offered a $150 spa, food, or slot free-play credit for your birthday; today, if you're lucky you get a meal voucher in the mail, and that's only if you're a local who's shown consistent play; there's nothing for out-of-towners.
Nevada Palace used to be the best play for a birthday bonanza, offering a free T-shirt and coffee mug, a voucher valid for double pay if you hit a royal on your special day and, if you returned the following day, a prize balloon that included perks like coin bonuses, hotel stays, and other gifts. But the Nevada Palace closed more than a half-decade ago and no one else has stepped up to the plate since.
By the same token, Santa Fe Station's long-running $25 table bet was, for a long time, the best birthday promo out there and you didn't even have to be a member of the player's club -- all you had to do was present valid ID. But this, we learned thanks to your question, was also discontinued some time ago (longer than the year-and-a-half that the shift supervisor with whom we spoke had been working there). Yikes! All that's left of much substance is the Jerry's Nugget offer of an $8 dinner voucher, $15 of bingo, or two games of bowling during your birthday month, and 10,000 free points ($10 value) if you swipe your card at Aliante (within 10 days either side of the date).
When it comes to restaurants, however, there are a few better options. Todai Asian/sushi buffet in the Miracle Mile at Planet Hollywood continues to offer a completely free buffet (food only) to the birthday boy or girl, provided there are an additional three full-paying adults in your party; otherwise, it's 50% off. Just present a valid I.D. The Artisan non-gaming boutique hotel offers guests (you don't have to be physically staying there) a complimentary bottle of Skyy Vodka on their birthday if you're there to party. Register online with Benihana's Chef's Table program and receive a $30 birthday certificate good for the month of your birthday (the Vegas venue is located at LVH), while members of Hooters' eClub receive 10 boneless wings on their birthday.
That, however, is about the sum of anything we know of that's conceivably worth traveling for, aside from the odd free dessert here and there. Kona Grill at Boca Park used to offer $15 off the check on your birthday, but when we called to ask if that was still the case they responded in the negative, although they did offer us a cupcake. Ditto Origin India, where they informed us that they no longer offer a free entree on your birthday.
If anyone knows of a good freebie we missed, do please drop us a line; in the meantime, it never hurts to ask, so if you inform the restaurant before you arrive, or at least at the time you're seated, that you or someone in your party is celebrating, you never know what little surprise the kitchen may rustle up to make your special day just that bit more special. Good luck, and Happy Birthday!